State-of-the-art switches, commonly known as switch boxes, are usually composed by a body and a cover and contain inside them a rotating element or indicator operatively connected to the shaft of the valve or actuator contained in the body.
The stem or rotating shaft is, for example, used in connection with cams operating further devices, such as analogical meter or similar.
The rotating organs are often fitted with visual indicators of the angular position of the valve or actuator shaft, so as to provide a visual indication of the functioning status of the valve or actuator.
Such visual indicators are usually housed on the cover so that they are visible from outside the switch.
For reasons of safety regulations, the switches are preferably made from a body and cover directly screwed onto the body through a threading coaxial with the valve or actuator shaft.
Such state-of-the-art devices have many drawbacks and limitations.
In fact, if the cover is not correctly centred on the body, the rotating shaft, which passes through the inside of the body and is supported in its rotation by the cover, inevitably tends to seize and break.
Furthermore, after the cover has been screwed onto the body, it is not easy to set the visual indicators on the zero position. This is essentially due to the fact that the screwing of the cover onto the body prevents the obtainment of a fixed and repeatable position of the stroke end of the cover.